How Vulnerable Is G.P.S.?
In the cool, dark hours after midnight on June 20, 2012, Todd Humphreys made the final preparations for his attack on the Global Positioning System. He stood alone in the middle of White Sands Missile Range, in southern New Mexico, sixty miles north of Jurez. All around him were the glowing gypsum dunes of the Chihuahuan Desert. In the distance, the snow-capped San Andres Mountains loomed.